It found that 672 people were fired for "unsatisfactory attendance" and 54 were disciplined for "unauthorized absence".
The average number of sick days a year at the department was 7.4 per employee with a total of 700,890 workdays lost. Stress accounted for one in 10 days lost to sickness.
Michael Stephens, UK general manager at Lifesize thinks flexible working could be key to reducing staff absence, he said: "We know that flexible working can produce a far more productive and motivated workforce, as well as having a wider impact on the overall workplace environment.
"Companies should consider offering disgruntled employees with alternative ways to get to work."
The figures also revealed that the Ministry of Justice took the most days off ill - an average of 8.9 - with 21.7% of the 635,554 sick days being attributed to stress.
The figures were released this month under the Freedom of Information Act.
